How difficult is this sound classification?
I think if you got the dataset, then a standard 1d convolutional neural network would work to some extent. It's not that there is some property of nearby sounds that it would pick up on. It would just memorize all the sounds that tend to come from your desk. I think the coding part would be pretty standard stuff. But collecting the data will be hard. You have to get a really big labeled dataset of sounds coming from your desk and sounds coming beyond a 3 foot radius. This dataset has to be realistic and representative of the real world. Getting that dataset would be pretty tricky but it is doable if you put multiple microphones in your house in order to triangulate the exact positions of all sounds. It would be like GPS but using sounds waves instead of light waves.